#9412, #9449. Stack backtrace provided by Neil Hoggarth - thanks.
* Repair --logfile, broken in 6.3.5. BerliOS Bug #9059,
reported by Brian Harring.
+* Robustness: If a stale lockfile cannot be deleted, truncate it to avoid
+ trouble later if the PID is recycled by a non-fetchmail process.
# TRANSLATIONS:
* New en_GB (British English) translation by David Lodge.
fclose(lockfp); /* not checking should be safe, file mode was "r" */
if (args == EOF || args == 0 || kill(pid, 0) == -1) {
+ /* ^ could not read PID || process does not exist */
+ /* => lockfile is stale, unlink it */
pid = 0;
-
fprintf(stderr,GT_("fetchmail: removing stale lockfile\n"));
if (unlink(lockfile)) {
if (errno != ENOENT) {
perror(lockfile);
+ /* we complain but we don't exit; it might be
+ * writable for us, but in a directory we cannot
+ * write to. This means we can write the new PID to
+ * the file. Truncate to be safe in case the PID is
+ * recycled by another process later.
+ * \bug we should use fcntl() style locks or
+ * something else instead in a future release. */
+ if (truncate(lockfile, (off_t)0)) {
+ /* but if we cannot truncate the file either,
+ * assume that we cannot write to it later,
+ * complain and quit. */
+ perror(lockfile);
+ exit(PS_EXCLUDE);
+ }
}
}
}
/** Check the state of the lock file. If there is an error opening or
* reading the lockfile, exit with PS_EXCLUDE. If a stale lock file
- * cannot be unlinked, complain, but continue. \return
+ * cannot be unlinked, complain and try to truncate it to 0 size. If
+ * truncation fails, complain and exit with PS_EXCLUDE. \return
* - 0 if no lock is set
* - >0 if a fetchmail is running, but not in daemon mode
* - <0 if a fetchmail is running in daemon mode.